We are made up of matter. Matter consists of molecules and atoms. These are made up of protons and neutrons in a nucleus, and electrons in orbit around them.
Ever see a representation of an atom?
Ever see the solar system?
Pretty similar (depending on the atom).
But, if you look really close at what is there, you'll see protons, neutrons and electrons are little packets of energy. I asked about the solar system to help us understand about the space between the nucleus and the electrons circling it.
When you look at an atom is there more space, or more substance?
If a very frightening way, we see far more space. That means, that when you look at it we are made up of mostly empty space.
Doesn't it make you wonder?